Pile driving hammer



Aug. 4, 1953 N. G. BELL PILE DRIVING HAMMER 3 Sheets-Sheet 1 Filed April 16, 1951 f o t n e u n I Attorney lg- 4, 1953 N. G. BELL 2,647,373

PILE DRIVING HAMMER M Attornev Aug- 4, 1953 N. G. BELL 2,647,373

PILE DRIVING HAMMER Filed April 16. 1951 3 sheets-sheet 3 Inventor /l/a/ @0A/Aff 55a.,

7 Attorney Patented ug. 4, 1.9515;

' OFFICE PILE DRIVING HAMMER Noel Gonne Bell, South Kensington, London, England Application April 16, 1951, Serial No. 221,139

In Great Britain April Z0, 1950 This invention relates to the type of pile-driving hammer that is operated by gaseous pressure iluid supplied from an external source, such as steam or compressed air, and comprises a piston stationary in relation to the object to be struck, a cylinder reciprocable longitudinally of the piston to form the ram that strike the blows, and an automatic pressure-fluid control valve mounted on a stationary part of the hammer not struck by the ram.

rlihe invention provides an improved hammer of this type, principally characterised in that the automatic control valve is mounted inthe piston and has actuating means projecting into or through a slot or groove provided in the cylinder.

This arrangement enables the provision. of valve mechanism in which the planes of movement of the valve and of its striking member are parallel to, instead of at right angles to, each other, thereby greatly reducing wear onthe valve mechanism and dispensing with the use of a camrod. It also enables an upper piston rod and a sealing gland therefor in the cylindercover to be eliminated, consequently reducing the overall length of the hammer and the headroom that it requires. It also enables the hammer tobe made double-acting. It further enables the hammer to be more easily adapted for extracting piles.

The invention will be clearly understood from the following description aided by the accompanying drawings which show some embodiments by way of example.

Figs. 1 to 4 of the drawings show a single-acting hammer embodying the invention; Fig. 1 repre' sents the hammer in longitudinal section in the plane I-I of Fig. 4; Fig. 2 represents a longitudinal section in the plane II--II of Fig. 4; Fig. `3 is an elevation in the plane III-III of Fig. 4; and Fig. 4 represents a cross section in the plane IV-IV of Fig. 1.

Figs. 5, 6 and '7 are views respectively similar to Figs. l, 2 and 3 but of a double-acting hammer.

Fig. 8 is a part view similar to Fig. 5 of a modified form of double-acting hammer.

Figs. 9 and 10 represent forms of the automatic valve in cross section.

Figs. 11 and 12 are views similar to Figs. 1 and 4 and show a modified form of single acting hammer.

Throughout the several figures the same references are used to denote the same or similar parts.

Referring more particularly to Figs. 1 to 4 the hammer comprises a stationary piston I attached to the top of a piston rod 2, which rests on the pile, and a cylinder 3 surrounding both the piston and the piston rod to form the ram that reciprocates relative to the piston. The cylinder 3, which is suitably guided, has a longitudinal slot 4 greater in length than the length of stroke of the cylinder to aiord an exhaust port, to allow for c-onnection of a pressure fluid supply conduit 5, and to allow for the projection of the automatic control valve actuating means. The automatic .control valve is a semi-rotary valve 6 mounted inside the piston I with its actuating means, namely its spindle 9, projecting through the slot 4. The valvechamber has ports 'I and 8 leading to the top of the piston and to atmosphere respectively; and the pressure fluid supply conduit 5 (see Figs 3 and 4) is connected to the valve chamber in the piston through the slot 4 as already mentioned. A lever I0 attached to the valve spindle 9v is adapted to be operated by cams II and I2 mounted on the cylinder 3, in or adjacent to the slot 4v therein.

When pressure fluid is turned on to the supply conduit 5 it flows past the valve 6 to the port I leading to the cylinder space above the piston I and forces up the cylinder or ram 3 from the position shown in Figs. 1 to 3. As the top of the slot 4 in the cylinder 3 approaches the top of the piston, the valve 6 is turned by the cam I2 to cut ofc' the supply of pressure uid and connects the port 1 with the port 8, whereupon fluid from the cylinder chamber above the piston is free to exhaust through the slot 4 in the cylinder, partly Aby way of these ports but mainly direct through to form a second pressure chamber I3 in the lower part of the cylinder 3, and by also providing: a ductl I6 connecting the port 8 to the bottom of the piston, a new lever IDA, a second pair of cams IIA and I2A, and sealing rings I4 or a gland in the bushing surrounding the piston rod 2. In this form as the cylinder rises and the top of the slot 4 vapproaches the top of the piston, the cam I2A turns the valve to connect the port 'I with the port 8 and uid exhausts as before. As the cylinder continues to rise, the bottom of the slot 4 covers the lower piston head and as the cylinder approaches the top of stroke, the cam I2 turns sobre 3 the valve 6 farther so as to admit pressure uid through the duct I6 leading to the bottom of the piston. As the cylinder 3 descends and the bottom of the slot i4 in the cylinder approaches the lower piston head, the cam I IA throws the valve S back to its previous intermediate position and cuts off pressure fluid from the duct I6 leading to the bottom of the cylinder and connects this duet i6 to the port l leading to the top ol the cylinder whereupon pressure fluid exhausts via the slot il. The cylinder continues on its down stroke and operates as described for single-action.

Reaction for the pressure uid on the down stroke is provided by connecting the bottom of the piston rod 2 to the pile or to an anvil I5 connected to the pile or by connecting .the piston I to the pile by members projecting through slots in the cylinder 3. The manner of connecting the anvil I5 to the pile may be by means of gripping jaws similar to those used on pile extractors.

`At the start of driving, when there may not be sumcient reaction, the double-acting hammer may be made to work on single-action only by controlling the admission of pressure iiud by means of a valve at the external source so as to shorten the stroke and prevent the cam I2 from coming into operation.

When desired the double-acting hammer may be made to work at full stroke on single-action only, by removing the cam I2.

In a modied form of the hammer shown in Figs. 5 to '7, the duct I6 (Fig. 5) may be omitted and the arrangement of valve ports, the lever I and thev cams I I and l2 may be the same as shown in Figs. 1 to 4. In this form air may be compressed in the lower cylinder chamber I3 on the up stroke to accelerate the fall of the cylinder on the down stroke, and thus require less'movement of the valve than that required for double-action.

Furthermore, the lower cylinder chamber I 3 may f be closed, as shown in Fig. 8, and a decompression valve I'I may be provided in the chamber I3 to allow for single-action working. The valve I'I may be placed in the bottom of the piston I, preferably in the form of a manually controlled tappet valve placed in the tcp of the piston rod 2.

If desired, the pressure fluid conduit 5 may be connected to the chamber of the valve 6 through a separate slot 4 in the cylinder, as shown in Figs. 8, 11 and l2.

In another form, the'lower cylinder chamber I3 is closed, as before described, and three ports l, 8 and I3 are provided in the chamber of the valve 6, as shown in Fig. 10, the port 8 leading to atmosphere and the ports l and I8 leading tothe top and the bottoni of the piston I respectively. A wide D valve 6A is provided connecting the three ports l, 8 and I8 so that the top and bottom cylinder may be simultaneously connected to atmosphere. With this wide D valve 6A, the hammer caribe operated on double-action or, by restricting length of stroke by controlling admission of pressure fluid by means of a valve at the external source on single-action. If it is not desired to use single-action, the required movement of the valve E may be reduced by using a narrow D valve 5 as shown in Fig. 9 which oonnects alternately the port leading to one cylinder to that leading to atmosphere while allowing pressure uid to admit to the port leading to the other cylinder.

If desired, either or both pressure chambers and their corresponding pistons may be made longer than the stroke of the cylinder to prevent the slot in the cylinder passing over the piston rings.

Hammers as herein described may be adapted for extracting piles by suitable positioning of the cams II, HA, i2 and IZA so as to cushion the downward blow and shorten the upward stroke.

A cradle guide I9 (Fig. 7) may be provided to support the hammer instead of a pile frame or leaders when desired. The cradle may be attached to the anvil I5 and may have longitudinal members extending above the anvil to guide the hammer and also below the anvil to engage the pile. The hoisting rope may be attached to the anvil or the cradle, to avoid the necessity of disconnecting the rope before starting operation of the hammer.

The cams may be mounted in the slot 4, as before mentioned, and the cylinder may be strengthened at the slot fl by providing a tying member, or members, outside and across the slot, as shown in Figs. 11 and l2.

When it is not desirable to have projections outside the cylinder 3, as for example when driving inside a tube, all the forms described may be further modified by omitting the connection of the pressure fluid supply conduit 5 through the slot 4 in the cylinder and connecting the supply conduit instead in the known manner to an upper hollow piston rod which is attached through the tcp of the piston I to the valve chamber and `projects through a gland in the top of the cylinder.

I claim:

l. In a pile driving hammer of the type operated by a gaseous pressure fluid supplied from an external source, the combination of a piston and piston rod stationary in relation to the object to be struck, a cylinder that reciprocates longitudinally with respect to the piston an-d piston rod to form the ram that strikes the blows, a rotary automatic pressure fluid control valve housed in the piston, a spindle projecting from the valve into a longitudinal slot formed in the circumferential wall of the cylinder, a-lever carried by the spindle, and means mounted on the cylinder for actuating the lever as the cylinder reciprocat'es.

2. A hammer according to claim 1, including a pressure fluid supply conduit connected to the valve housing through said longitudinal slot in the wall of the cylinder.

3. A hammer according to claim l, having a second longitudinal slot formed in the circumferential wall of the cylinder, and a pressure uid supply conduit connected to the valve housing through said second longitudinal slot.

4. In a pile driving hammer of the type operated by a gaseous pressure fluid supplied from an external source, the combination of a piston and piston rod stationary in relation to the object to be struck, a cylinder that reciprocates longitudinally with respect to the piston and piston rod to form' the ram that strikes the blows, a rotary automatic pressure iluid control valve housed in the piston, a spindle projecting from the valve into a longitudinal slot formed in the circumferential wall of the cylinder, a lever carried by the spindle, and means mounted on the cylinder for actuating the lever as the cylinder reciprocates, said piston being extended to form a second piston head, a pressure fluid conduit leading from said second piston head to the valve housing, and a second pressure chamber formed in the lower part of the cylinder to enable the hammer to be used on double-action.

5. A hammer according to claim 4, in which a space is aorded between the bottom of the longitudinal Slot in the cylinder and the lower piston head to allow air to exhaust from the lower cylinder for part of the upward stroke thereby to enable a double-acting hammer to work on short stroke single-action.

6. In a pile of driving hammer of the type operated by a gaseous pressure uid supplied from an external source, the combination of a piston and piston rod stationary in relation to the object to be struck, a cylinder that reciprocates longitudinally with respect to the piston and piston rod to form the ram that strikes the blows, a rotary automatic pressure fluid control valve housed in the piston, a spindle projecting from the valve into a longitudinal slot formed in the circumferential wall of the cylinder, a lever carried by the spindle, and means mounted on the cylinder for actuating the lever as the cylinder reciprocates, said piston being extended to form a second piston head, a second pressure chamber formed in the lower part of the cylinder to allow atmospheric air to be compressed in said second pressure chamber and thus reduce the movement of the valve to less than that required for normal double-action with pressure fluid.

7. A hammer according to claim 6, including a decompression valve in the lower pressure chamber to enable the hammer to work on single-action.

8. In a pile driving hammer of the type operated by a gaseous pressure nuid supplied from an external source, the combination of a piston and piston rod stationary in relation to the object to be struck, a cylinder that reciprocates longitudinally with respect to the piston and piston rod to form the ram that strikes the blows, a rotary automatic pressure uid control valve housed in the piston, a spindle projecting from the valve into a longitudinal slot formed in the circumferential wall of the cylinder, a lever carried by the spindle, and cams mounted on the cylinder for actuating the lever as the cylinder reciprocates, said cams capable of being positioned to cushion the downward blow and shorten the upward stroke of the cylinder at will to enable the hammer to be used for extracting piles.

9. In a pile driving hammer of the type operated by a gaseous pressure fluid supplied from an external source, the combination of a piston and piston rod stationary in relation to the object to be struck, a cylinder that reciprocates longitudinally with respect to the piston and piston rod to form the ram that strikes the blows, a rotary automatic pressure iluid control valve housed in the piston, a spindle projecting from the valve into a longitudinal slot formed in the circumferential wall of the cylinder, a lever carried by the spindle, means mounted on the cylinder for actuating the lever as the cylinder reciprocates, an anvil at the bottom of the piston rod, and a cradle guide attached to the anvil to support the hammer on the object to be struck.

NOEL GONNE BELL.

References Cited in the le of this patent UNITED STATES PATENTS Name Date Haage Aug. 30, 1938 FOREIGN PATENTS Number Number 

